Telephone-diaphragm.



F. HOYT.

TELEPHONE DIAPHRAGM. APPLICATION FILED OCT. 25, 1916.

l ,26 1 ,3 9 1 a v Patented Apr. 2, 1918.

(a 4/ A w l 0 Y I/ i 7- FRED HOYI, OI SEATTLE, WASHINGTON, ASSIG-NOR 'I'O HIGH POWER TELEPHONE COMPANY, OF KING COUNTY, WASHINGTON.

TELEPHONE-DIAPHRAGM.

Specification of Letters Eatent.

Patented Apr. 2, l%l*8.

Application filed October 25, 1916. Serial No. 127,524.

true, and exact specification.

- means of a cap My invention relates to improvements in transmitter diaphragms and means for holding the same, and has for its principal object to provide an improved and novel means for mounting a vibrating diaphragm in a sound transmitter; to provide an improved type of diaphragm which approximates an unrestrained diaphragm. It has long been known that a diaphragm which is not restricted against free vibration will respond to high notes and small changes in pressure much'more readily than one which offers physical resistance.

Other objects will appear as my invention is more fully explained in the following specifications, illustrated in the accompanyingdrawings, and pointed out in the ape pended claims:

In the drawings Figure 1 is a cross sec-- tional elevation of my device. Fig. 2 is a plan view of my improved diaphragm.

Referring more articularly to the drawings, numeral 1 in icates a ermanent magnet to which cores 2 of coi s 3 are secured. All of the above mentioned parts are mounted in a receiver casing 41: and are simi-- lar in. many respects to the well-known Stromberg-Carlson receiver. of easing 4 is threaded and screws into a diaphragm housing 5 and is held securely by means of a lock nut 6. A diaphragm 7 is mounted against the lower face of diaphragmhousing 5 and is held in place by 8 Dia hragm 7 is provided with a plura 'ty-pre crab y threelugs 9 which extend radially from the diaphragm and are clamped between the diaphragm housing 5 and cap 8 by means of bolts 10. The diaphragm roper is of slightly smaller diameter than t e inner or core portion of the housing 5 and the cap 8 so that it is not restrained by the housing and cap except at the lug points. Tubular ackmg rings 11 which are preferably of ru her, are mounted on either side of the dia hra as to preventexeessive vi ration but not to The lower end,

proper so offer a very extensive resistance to the free movement of the diaphragm; I prefer to have the lugs perforated as at 12 so that the bolts may pass therethrough, but this is not necessary as it might be frictionally retained. I have found that my improved diaphragm is much more flexible than ,the usual dlaphragm, that it responds to much higher notes, does not squawk and gives a much improved articulation. I prefer a thin steel diaphragm; however, other material may be use While I have shown a particular form of embodiment of my invention, I am aware that many minor changes therein will readily suggest themselves to others skilled in the art without departing from the spirit and scope of the invention, and I therefore desire to avoid beinglimited to the exact form shown and described.

Having described my invention, what I claim as new and desire to protect by Letters Patent, is

1. A telephone transmitter comprising a' hollow head, a hollow cap having a central opening and fitted to the face of the circular head, a circular diaphragm having radial extensions which fit between the face of the circular head and the hollow cap, the circular diaphragm between the radial projections being of less diameter than the inner diameter of the circular head, an annular resilient washer interposed between one face of the diaphragm and the inner portion of the hollow head, a similar annular resilient washer interposed between the other face of the diaphragm and the hollow cap, and

permanent electromagnets located in rear of the diaphragm. V

2. A telephone transmitter comprising a hollow circular head, a hollow cap fitted on the hollow head, a circular diaphragm having radial extensions which fit between the hollow head and the hollow cap, bolts extending through the head cap and the radial extensions, the circular diaphragm between the radial extensions being of less diameter than the inner diameter of the. hollow head,

and the hollow cap, tubular resilient washf ers interposed between the diaphragm and the hollow head and the hollow cap, and permanent electromagnets located behind the diaphragm.

' FREDHOYT. 

